LVM修改swap交换分区大小
为了更好的感受CentOS，我决定把虚拟机的内存从512减少到256，哈哈~~~
关机，修改，重启。
然后再检查一下，没必要的服务全关掉，进程kill掉。
发现交换分区比较碍眼，然后发现是LVM的，然后就是改这里了。。。
先找到交换分区，fdisk里没有，google了一下只有到/etc/fstab找了。
[root@centos01 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00 19G 4.0G 14G 23% /
/dev/sda1 99M 12M 82M 13% /boot
tmpfs 125M 0 125M 0% /dev/shm
.host:/ 193G 6.1G 187G 4% /mnt/hgfs
[root@centos01 ~]# cat /etc/fstab
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/VolGroup00/LogVol01 swap swap defaults 0 0
其实这里也有。。
[root@centos01 ~]# cat /proc/swaps
Filename Type Size Used Priority
/dev/mapper/VolGroup00-LogVol01 partition 1048568 0 -1
这里只有一个卷组，2个卷，一个是根分区，一个是swap分区。
[root@centos01 ~]# vgdisplay -v
Finding all volume groups
Finding volume group "VolGroup00"
--- Volume group ---
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 19.88 GB
PE Size 32.00 MB
Total PE 636
Alloc PE / Size 636 / 19.88 GB
Free PE / Size 0 / 0
VG UUID ASOZ1Q-lv3w-Mp8e-NbrI-KJyT-Z0fo-L5XsB2
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID eavv3T-mYNr-UZSO-rgUS-RqAb-fwQT-FfK3fT
LV Write Access read/write
LV Status available
# open 1
LV Size 18.88 GB
Current LE 604
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID zbtJp1-THIO-XHRQ-qpv1-PRRp-Wuqt-Ls4RFO
LV Write Access read/write
LV Status available
# open 1
LV Size 1.00 GB
Current LE 32
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Physical volumes ---
PV Name /dev/sda2
PV UUID LUO0ND-cQIi-N60M-GlnC-CDsa-7JMn-NQrBNL
PV Status allocatable
Total PE / Free PE 636 / 0
目标找到了，开工！！
这里分几部：
1、停掉swap分区
2、缩小swap对应卷的大小，同时增加根分区卷大小（资源不能浪费了！！）
3、同步卷
4、重做swap分区
5、DONE
[root@centos01 ~]# free
total used free shared buffers cached
Mem: 255444 143904 111540 0 14088 107696
-/+ buffers/cache: 22120 233324
Swap: 1048568 0 1048568
[root@centos01 ~]# swapoff -a
[root@centos01 ~]# free
total used free shared buffers cached
Mem: 255444 143432 112012 0 14100 107696
-/+ buffers/cache: 21636 233808
Swap: 0 0 0
[root@centos01 ~]# lvreduce /dev/VolGroup00/LogVol01 -L -512M
WARNING: Reducing active logical volume to 512.00 MB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce LogVol01? [y/n]: y
Reducing logical volume LogVol01 to 512.00 MB
Logical volume LogVol01 successfully resized
[root@centos01 ~]# lvextend /dev/VolGroup00/LogVol00 -L +512M
Extending logical volume LogVol00 to 19.38 GB
Logical volume LogVol00 successfully resized
[root@centos01 ~]#
[root@centos01 ~]# vgdisplay -v
Finding all volume groups
Finding volume group "VolGroup00"
--- Volume group ---
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 5
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size 19.88 GB
PE Size 32.00 MB
Total PE 636
Alloc PE / Size 636 / 19.88 GB
Free PE / Size 0 / 0
VG UUID ASOZ1Q-lv3w-Mp8e-NbrI-KJyT-Z0fo-L5XsB2
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID eavv3T-mYNr-UZSO-rgUS-RqAb-fwQT-FfK3fT
LV Write Access read/write
LV Status available
# open 1
LV Size 19.38 GB
Current LE 620
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID zbtJp1-THIO-XHRQ-qpv1-PRRp-Wuqt-Ls4RFO
LV Write Access read/write
LV Status available
# open 0
LV Size 512.00 MB
Current LE 16
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Physical volumes ---
PV Name /dev/sda2
PV UUID LUO0ND-cQIi-N60M-GlnC-CDsa-7JMn-NQrBNL
PV Status allocatable
Total PE / Free PE 636 / 0
已经改变了，但是还需要同步卷上的文件系统。
[root@centos01 ~]# resize2fs /dev/VolGroup00/LogVol00
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/VolGroup00/LogVol00 is mounted on /; on-line resizing required
Performing an on-line resize of /dev/VolGroup00/LogVol00 to 5079040 (4k) blocks.
The filesystem on /dev/VolGroup00/LogVol00 is now 5079040 blocks long.
[root@centos01 ~]# resize2fs /dev/VolGroup00/LogVol01
resize2fs 1.39 (29-May-2006)
resize2fs: Bad magic number in super-block while trying to open /dev/VolGroup00/LogVol01
Couldn't find valid filesystem superblock.
交换分区不包含有效的文件系统，不能被同步，需要重建。
[root@centos01 ~]# mkswap /dev/VolGroup00/LogVol01
Setting up swapspace version 1, size = 536866 kB
[root@centos01 ~]# swapon -a
[root@centos01 ~]# free
total used free shared buffers cached
Mem: 255444 165340 90104 0 33768 109300
-/+ buffers/cache: 22272 233172
Swap: 524280 0 524280
DONE
博客园用起来感觉也很不爽！！！OneNote发布居然告诉我不支持图片！！！！
